Hydrochloric Acid → 4-Piperidinol, 1-(2-hydroxy-2-methylpropoxy)-2,2,6,6-tetramethyl-

Participants

Reaction Conditions

Reaction Steps

A solution of 17.2 g (100 mmol) of 4-hydroxy-1-oxyl-2,2,6,6-tetramethylpiperidine dissolved in 50 mL of water and a solution of 25.3 g (0.37 mol) of 50% aqueous hydrogen peroxide are added simultaneously over 3-3.5 hours at 40° C. to a mixture of 0.27 g (1.0 mmol) of ferric chloride hexahydrate, 25 mL of water, 1.1 mL of 37% hydrochloric acid and 200 mL of tert-butyl alcohol. About two hours into the addition, 0.5 mL of 37% hydrochloric acid is added to the reaction mixture. After the peroxide addition is complete, 1.2 mL of 37% hydrochloric acid is added and the reaction mixture is heated at 40-50° C. for 3.5 hours. The reaction mixture is stirred overnight at room temperature. The reaction is completed by adding two portions of 0.3 mL of 37% hydrochloric acid while heating the reaction mixture at 45° C. for 5.5 hours. Work-up is done as in Example 20 and affords 21.5 g (88% yield) of the title compound as a white solid. Gas chromatography shows the product has a purity greater than 96%.

Provenance & Evidence